I squatted Wikidata page on Meta [1] and added there a summary of
present projects, needs etc. for which I know (or remembered).
This field is very complex, needed, but neglected on Wikimedia
projects (exception is French Wikipedia).
For now, it is a summary page. However, I hope that it will initiate a
real organized work on this issue.
[1] -
http://meta.wikimedia.org/wiki/Wikidata